Types of skin cancer: basal cell, squamous cell and melanoma explained
Skin cancer is the most common cancer in the United States. Most cases are linked to ultraviolet (UV) light from the sun or tanning beds. Knowing the main types helps you recognize changes early, when treatment works best. This page is educational only and is not a substitute for a skin exam by a doctor.
Basal cell carcinoma (BCC)
According to the American Academy of Dermatology: Types of skin cancer, basal cell carcinoma is the most common type of skin cancer. It often appears on sun-exposed areas such as the face, ears, neck and scalp. It can look like a shiny, pearly bump, a pink patch, a sore that bleeds and doesn't heal, or a scar-like area. BCC grows slowly and rarely spreads, but it can damage surrounding tissue if left untreated.
Squamous cell carcinoma (SCC)
Squamous cell carcinoma is the second most common type. It often appears as a rough, scaly patch, a firm bump, or a sore that heals and reopens, usually on skin that gets a lot of sun. It can spread if not treated, so new or changing spots should be checked.
Melanoma
Melanoma is less common but more likely to spread, which makes it the most dangerous of the three. It can develop in an existing mole or appear as a new dark spot. The ABCDE warning signs (Asymmetry, Border, Color, Diameter, Evolving) are a practical way to check moles; see our ABCDE mole check. The National Cancer Institute: Skin cancer pages describe melanoma risk factors, including many moles, fair skin, a history of sunburns and family history.
The UV connection
UV exposure is the major preventable risk factor for all three. Indoor tanning raises risk (see tanning beds and UV risk), and so do repeated sunburns. Medical journals have also published case reports of changing moles and melanoma in people using unapproved melanotan products (see melanotan, moles and melanoma).
When to see a dermatologist
- A new spot that looks different from your other moles.
- A mole that changes in size, shape or color.
- A sore that doesn't heal within a few weeks.
- A spot that itches, bleeds or crusts.
The Skin Cancer Foundation: Skin cancer information pages have photos and more detail on each type. Regular self-checks plus a professional exam if you're at higher risk are the best way to catch skin cancer early.
Published October 27, 2026. Sources are linked in the text. See our Medical Disclaimer.